1. Field of the Invention
The present invention is directed to a portable, telescoping tower assembly that may be mounted on a standard trailer, vehicle, skid, or barge for rapid deployment to support equipment at desired heights. In particular, the present invention is directed to a portable, telescoping tower assembly including a series of telescoping sections that extend for use and retract and nest together for storage and transportation.
2. Prior Art
Portable tower assemblies are known and are often used to support equipment at desired heights when rapid deployment is warranted or when circumstances are of a temporary nature which do not justify permanent installation. For example, cellular telecommunications services may be desirable at a sports facility or in disaster situations. Additionally, support of lighting equipment at sporting events may be desirable. Portable towers are also used in military operations for telecommunications and detection equipment.
The portable towers are often deployed in adverse conditions, such as desert or swamp locations, which are difficult on moving components. High wind conditions can also twist components of a tower.
In one type of portable tower system, a plurality of telescoping sections are vertically movable between a retracted, nested position and an extended position. The cross-section of the sections may be triangular, square, rectangular or other shapes. Although each of the telescoping sections are similar, the sections are progressively smaller in cross-sectional area. According, the sections have progressively decreasing horizontal dimensions. Ball bearings or other bearings may be utilized to permit movement between the sections. The bearings may provide extra weight and cost. Alternatively, if the dimensions are within certain tolerances, the framework of an inner section may ride on the framework of an adjacent section.
It is important that the sections be capable of relative movement during extension and retraction of the tower. If the sections become misaligned, the sections may become jammed, and retraction or extension of the sections will be difficult or be prevented.
Prior proposals for tower assemblies include the following:
Blagg (U.S. Pat. No. 3,494,593) discloses a portable mast moved by an electric motor with triangular sections having a vertical stanchion 100 at each corner. Each stanchion 100 includes a vertical guide 102 forming a vertical channel 104 within which lugs 106 and 108 are adapted to slide.
Eklund (U.S. Pat. No. 4,357,785) discloses a telescopic mast with each section having six planar sidewalls. Internal guide grooves 5, 6 and 7 receive guide blocks 8, 9 and 10 made of plastic having a high slidability such as a high molecular polythene alloyed with a lubricant.
Walther (U.S. Pat. No. 1,459,123) discloses a telescoping tower with a series of fillers 28 secured to inner sections by rivets 30.
Rowan (U.S. Pat. No. 2,715,954) discloses a vehicle mounted tower which may be pivotally raised or lowered.
Partlow (U.S. Pat. No. 3,439,467) discloses a telescoping tower with primary guides such as vertically extending grooves 46, 47 and auxiliary guides in the form of elongated plates 51. The tower includes an electrically driven motor 43 with suitable reduction gearing means.
Campbell (U.S. Pat. No. 3,958,376) discloses a tower with tower sections, each section being smaller in size than the next adjacent section. Tower sections 130 and 120 have collars 131 and 121 which are provided with rollers 132 and 122 which contact the outer surface of the next adjacent section.
Jouffray (U.S. Pat. No. 3,985,234) discloses a boom with telescopic elements slidably engaged within one another having slide shoes 23 which bear against a lower or inner V-shaped leg 18 to self-center the elements with respect to each other.
Roberts et al. (U.S. Pat. No. 4,932,176) discloses a telescoping mast system moved between a horizontal stowed position and an upright operating position.
Harrel, Jr. et al. (U.S. Pat. No. 5,537,125) discloses a vehicle mounted broadcast antenna tower and a pair of hydraulic pistons 28 that move the tower from horizontal to vertical.
Lavin (U.S. Pat. No. 5,557,892) discloses a mast with bearings 100 mounted at the inside of each mast section, to slide up and down the outer mast section.
Norwood (U.S. Patent Application Publication No. 2006/0028390) discloses a cell phone telescoping tower raised or lowered from storage to operating position by hydraulic cylinder.
Notwithstanding the foregoing, there remains a need to provide a portable, telescoping tower assembly which is simple and cost effective to construct and operate.
Accordingly, it would be desirable to provide a portable, telescoping tower assembly with a guide mechanism that will permit efficient and rapid deployment and retraction of the sections of the telescoping tower.
It would also be desirable to provide a guide mechanism for adjoining sections of a tower assembly which are simple to construct, efficient to operate, and which does not require any lubrication.
It would also be desirable to provide a portable tower assembly with telescoping sections having guides that are easily replaceable.